What does it mean by 'sufficient vacuum is needed to properly operate an automatic transmission'?

 

What is "it"? No vacuum is used on a 4L60E for operation/control.

 

I was told that with larger intake manifold ports such as the LT4, A4's don't run too good. I appreciate your help shoebox.

 

I've heard that too along with a larger throttle body will burn up the tranny. Never understood any of these since the 94 and above are all electronically controlled and don't run off a TV cable or vacuum. The only input the tranny uses is the TPS sensor and MPH I believe.